Set of key buttons for a handset



FIG. 1 is a front view of a set of key buttons for a handset showing our new design; and,

FIG. 2 is a perspective front view thereof.

The broken line showing of various disclaimed regions and remainder of the handset in the figures is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a set of key buttons for a handset, as shown and described. 